Electric mercury-motor meter.



No- 878,629. PATENTED FEB. 11, 1908;

R J. H. HODDE. ELECTRIC MERCURY MOTOR METER. APPiJIOATION FILED MAR. 16, 1907.

MIMI- WM "my $1M v Fig. 1, but showing a central cross-section of I .IAOOB H. HODDE, OF SPRINGFIELD,

ILLINOIS, ASSIGNORTO SANGAMO ELECTRIC COMPANY, I

OF SPRINGFIELD, ILLINOIS, A CORPORATION OF ILLINOIS.

ELEQTRIC MERCURY-MOTOR METER.

Specification of Letters Patent.

Patented Feb. 11, 1908.

Application filed March 16- 1907. Serial No. 362,775.

To all whom it may concern:

Be itknown that I, JACOB H..HODDE, a citizen of r the United States, residing at Springfield, county'of Sangamon, State of I inois, have invented certain new and useful Improvements in Electric Mercury-Motor Meters, of which the following is a specification, reference being had to'the accompanying drawings.

My invention relates to improvements in electric mercury motor imeters. In this type of meter, as is well known, the armature, usually a copper disk, is mounted on a vertical spindle and immersed in mercury. This disk is usually amalgamated, completely or in part, before being placed in the meter, but even when thisis not done thecopper disk soon becomes more or less completely amalgamated in ordinary use. When such a. meter having the more'or less completely amalgamated armature immersed in mercury is shaken about, :as it must be necessarily in shipment, the amalgam oxidizes and rises to the surfaceof the mercury. This oxidized amalgam or dross, gathering about the s indle and filling up the depression about t 1e spindle caused by capillarity, as will be readily understood,and'form ing a cohesive film on the upper surface of the mercury, adheres to the spindle and to the body of the mercury, having a considerable retarding effect upon the-armature on light load current, and causing the meter on such load to register considerably less than the amount of power: actually used.

The object of this-invention is to provide means by which this retarding effect may be overcome or made so small as to be unappreciable. I accomplish this object by the means illustrated in the drawings and hereinafter described.

What I consider as new is pointed out in the claims.

In the drawings :Figure 1 is a side elevationof the meter. Fig. 2 is a view similar to the casing in which the mercury chamber is formed, and showingthe parts inside the casing in elevation; Fi 3 is an illustration of another form of the evice for. preventing the retarding effect of the dross. Fig. 4 is a detail, being a-section very much enlarged through one end of thewasher for the pur ose of showing the amalgamation on the ower surface.

Referring to the several figures of the drawings, in which corresponding parts are indicated by like reference characters, 10, 11 lindicate the two parts of the body of the casing in which is formed the mercury chamber 12 containing mercury 13. Submerged in the mercury are the armature 14 and flotation chamber 15, both non-rotatably secured on s indle 16 which is suitably journaled in the ordinary manner. N ear the upper end of the spindle is shown a braking disk 17 acted upon by permanent magnets; 18, as usual.

19 indicates the contacts entering the mercury chamber and adapted to carry the driving current. I I l 20 indicates an electro-magnet energized by coil 21 which is .to be connected up as desired. I As illustrated, the poles of the magnet 20 pierce the part 11 of the casing, the

fendsof the said poles being thus brought in close proximity'to the armature 14. 22 indicates a plate, preferably of soft steel, adapted toiserve as a return for the magnetic lines of force "from pole to pole of the magnet 20'.

preferably of non amalgamable metal, though it may be of any other suitable material,- surrounding the spindle 16, in the construction shown, and floating on the surface of the mercur It is not necessary that the washer shal float on the mercury, but only that it shall effectively protect the spindle at the oint where the spindle enters the body of plained. It is, of'course, necessary that the o ening in the washer shall be large enou h t iat the washer cannot bind on the spindle. It has been foundin practice that an opening having a diameter from ten to fifteen thousandths offan inch larger than the diameter of the .spindle produces very satisfactory results, but I do not wish to restrict myself to the-use of such a close-fitting washer, or other device In order that the washer shown shall not bind on the spindle in case the meter should be tipped slightly from its normal upright osition, I have reamed out the openi' g in t e washer from both sides, thus pres nting a minimum bearing surface to the-spindle, and reducing this objection as much as possible. This, of course, is not. ordinarily necessary to the proper working 0f the meter.

the mercury, as is hereinafter exstronger attraction for the dross, at thesame time 1t causes'said under surface to have a.

still stronger attraction for the mercury,

f which condition aids materially in getting cohesive body to the form of a fine dry powthis dross from under the washer.

As has 'been stated above, the body of the washer is preferably of non-amalgamable material. It has been found that this dross in the mercury does not adhere to a nonamalgamable material nearly sostrongly as it does to one that will amal amate oris amal amated. When a smal amount of this ross does work its way into the bearing between the spindle and the washer, the retardingeffect is not nearly so reat when such bearing is of non-amalgamab e material -asit would be if the bearing surface of the washer were amalgamable and had conse' quently a greater attraction for the dross.

It has been found that when the dross does get into the bearing as above suggested,it 1s very soon changed from a more or less der, and in this form gradually works itself out of the bearing so as not to retard the rotation of the spindle.

Fig. 3 shows another'construction of the part that surrounds the spindle at the surface of the mercury. In this form the device for shaped float 24 provided at each end with a through which the spindle preventing the accumulation of dross around the spindle 16 consists of a hollow cylindrical suitable opening 16 passes so that the said spindle rotates freeythereinv So faras I am aware, no one has heretofore contemplated providing a spindle rotating in mercury -'with a device for protecting the s indle 'as described, and this feature is t erefore claimed broadly. While I have described this device as a washer, this word,

it will of course be understood, in both the specification 'and the claims is used for convenience in description, and is to be under stood as referring to a device of the general character described and not to be limited to the stricttechnical meaning of the word.

.When the-washer or drum is made of non-.

amalgamable metal, it. will be readily understood that its under surface may be amalga mated in any well-known manner, such, for instance, as copper-plating its undersurface and amalgamating the plated surface. This construction is shown in Fig. 4, which'is a detail, showing a section of. the washer very; In this figure 23-indicates much enlarged. the disk; 25 the copper plating; and 26 the amalgamation 'of the copper plated surface.

' What I claim as my invention and desire" to secure by Letters Patent is 1. The combination with a I body of iner cury and a spindle rotating therein, of a washer loosely surrounding said spindle-at the point where the spindle enters the body of the mercury.

2. The combination with a body of,mer.

cury and a spindle rotating therein, of a washer floating on the surface of the mercury Y and loosely surrounding the spindle.

3. The combination with a body of mercury and a spindle rotating therein, of av washer loosely surrounding said spindle at,

the point where it-enters the bodyofthe mercury, said washer being amalgamated on.

its lower surface. I

'4. The combinationwith a body of mercury and a spindle rotating therein, of a washer of non amalgamable material. loosely surrounding said spindle at the point where i it enters the body of the mercury.

5.- The combination with a body of mercury and .a spindle rotating therein, of a washer of non-amalgamable material loosely. surroundingsaid spindle. at. the point where it enters the body of the mercury, said washerbeing-provided with an amalgamated I under surface.

6. The combination with b of mer;

cury and a spindle rotating ..therein," of a hollow drum loosely surrounding thespindle at the point where it enters the body of thi mercury.

' JACOB H; HODDE? Witnesses:

ROBERT C. LANPHIER,

ALBERT D. BIRNBAIIMr 

